Swivel chair

ABSTRACT

A swivel chair having a pedestal, a vertial nut revolubly mounted on the axis of the pedestal and having an enlarged flange frictionally engaged with the upper end of the pedestal, and a screwpost fixedly connected to the bottom of the seat of the chair, and threadedly engaged with said nut, lubricant being provided between the threads of the nut and post, the post at each end thereof having a stop to limit the fully raised and fully lowered positions of adjustment of the seat relative to the pedestal, and the mentioned friction retaining the nut nonrotational relative to the pedestal during height-adjusting movement of the seat and said nut rotating against the resistance of the mentioned friction when the seat is either in its fully extended or fully lowered positions, and, thereby, being swivelly movable while in such positions.

United States Patent [72] Inventor Raoul Hugh De Gaston Lynwood, Calif. [2]] Appl. No. 50,570 [22] Filed June 29, 1970 [45] Patented Nov. 16, 1971 [73] Assignee Henri L. Valette Long Beach, Calif.

[54] SWIVEL CHAIR 4 Claims, 3 Drawing Figs.

[52] US. Cl 248/405, 287/58 CT, 74/424.8 [51] Int. Cl ..F16m 1 1/00 [50] Field 0! Search 248/405, 406; 287/58 CT; 74/424.8 VA

[5 6] References Cited UNITED STATES PATENTS 482,553 9/1892 Fuhrmann 248/405 Primary Examiner-William H. Schultz Attorney-Hyman and Jackman ABSTRACT: A swivel chair having a pedestal, a vertial nut revolubly mounted on the axis of the pedestal and having an enlarged flange frictionally engaged with the upper end of the pedestal, and a screwpost fixedly connected to the bottom of the seat of the chair, and threadedly engaged with said nut, lubricant being provided between the threads of the nut and post, the post at each end thereof having a stop to limit the fully raised and fully lowered positions of adjustment of the seat relative to the pedestal, and the mentioned friction retaining the nut nonrotational relative to the pedestal during height-adjusting movement of the seat and said nut rotating against the resistance of the mentioned friction when the seat is either in its fully extended or fully lowered positions, and, thereby, being swivelly movable while in such positions.

SWIVEL CHAIR BACKGROUND OF THE INVENTION l. Field of the Invention Swivel chairs that are also height-adjustable.

2. Description of the Prior Art Swivel chairs that are height-adjustable are well known and have a wide range of use, mainly commercial. It is common for such chairs, when adjusted to their lowermost position, to be incapable of being swiveled thereby limiting the facility of use. It is also common for such chairs, when raised to their maximum height of adjustment, for them he become separated from the base or pedestal, whereby the person in the chair may fall with the separated chair and be injured.

SUMMARY OF THE INVENTION A pedestal having an upper cylindrical guide hole extending vertically downwardly and having an upper surface suitably arranged for frictional engagement with the flange on a flanged nut. Such nut being cylindrical is guided by and free to rotate in said hole in the pedestal. The flange of said nut being in frictional engagement with the upper surface of the pedestal, thereby supports said nut. A post is threadedly engaged with the nut and extends upwardly therefrom and is affixed to the bottom of a seat. Said post is provided with a stop at both its upper and lower ends, thus limiting the travel of said screwpost in the nut. Said post is usually lubricated. The nut flange being in frictional engagement with the top of the pedestal, retains the nut in nonrotational position while the height of the seat is being adjusted. The friction of the flange maintains the nut stationary because such friction is concentrated at a larger radius than the radius of the post and thus is able to assert a greater torque on the nut than is the screwpost. The seat, with its post and the nut engaged with the latter, as a unit, is readily separated from the pedestal for compact crating of the chair for shipment.

The primary object of the invention is to provide a swivel chair having the structural and functional characteristics above outlined.

This invention also has for its objects to provide such means that are positive in operation, convenient in use, easily installed in a working position and easily disconnected therefrom, economical of manufacture, relatively simple, and of general superiority and serviceability.

The invention also comprises novel details of construction and novel combinations and arrangements of parts, which will more fully appear in the course of the following description, which is based on the accompanying drawing. However, said drawing merely shows, and the following specification merely describes, one embodiment of the present invention, which is given by way of illustration or example only.

In the drawing, like reference characters designate similar parts in the several views.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a vertical sectional view of a swivel chair showing the height-adjustable parts thereof, the chair being shown in its highest adjusted position.

FIG. 2 is a cross-sectional view as taken on the line 2-2 of FIG. I.

FIG. 3 is a vertical sectional view of the height-adjustable parts of the chair, which is shown in its lowest adjusted positron.

DESCRIPTION OF THE PREFERRED EMBODIMENT The present swivel chair conventionally comprises a base 5 which is fixedly provided with a column 6, a seat 7, a threaded post or stem 8 fixedly extending downwardly from the seat, bearing means 9 in the upper end of said column, a nut 10 rotationally guided in the bearing means, and an upper flange 11 on said nut in frictional support engagement with the bearing means 9.

The base 5 may take any form, such as the stamped base plate 15, shown in FIG. 1, or radial legs such as commonly used for supporting chair columns. The present column 6 is shown as a metal tube 16, a reinforcing plate 17 at the bottom of the tube 16. The upper end of said tube is reinforced by spaced plates 18 and 19 which, in this case, embody the bearing means 9, said plates having axially aligned holes 20 that serve as bearings for the nut 10, as will be seen later.

The post 8 may be afi'lxed to the seat 7 in any suitable manner. In this case a fitting 21, secured to the bottom of the seat, has the stem affixed thereto and also serves to provide a downwardly facing stop 22. A second stop 23, here shown in the form of a cross pin, is provided at the lower end of the post. The latter is applied, after the nut 10 is threadedly engaged with the post.

Said unit has an elongated boy 24 with internal threads that are compliments of the threads on the post 8. The length of said body is at least as great as the spacing between the plates 18 and 19 and of a diametral size to slidingly'and rotationally fit the holes 20 in said plates. The post 8 is shown twice as long as the nut body 24, but the relative length of post and nut may be such as to provide the desired degree of raising and lowering movement of the seat.

The flange 11 is preferably substantially larger than the nut body 25 and, therefore, larger than the mentioned threads, the same being relieved at 25 to form an outer rim 26 that bears upon the upper surface of the upper plate 18. The relatively large frictional radius between said plate 18 and the rim 26 provides a frictional resistance to rotation of the nut 10 under the weight of the seat 7, whether vacant or occupied.

It will be clear that, due to the lubricant customarily provided between the threads of the post 8 and the nut 10, a torque of small degree is transmitted to the nut by the post during adjustment of seat height. Hence, during such adjustment, the nut does not turn, being retained against rotation by the friction created between the plate 18 and the rim 26 of the flange l 1. However, when either stop 22 or 23 encounters the nut, as shown in FIGS. 1 and 3, continued rotative movement of the seat will cause rotation of said nut by overcoming the above-mentioned friction between the nut and plate 18.

It will be evident that, regardless of the speed of rotation of the seat, in either direction, the operation is a safe one, since, when lowering the seat, there is no sudden stop that would cause the base to turn under the impact of stop 22 with the flange 11, such as may cause injury to a person in attendance on the person in the seat, and when raising the seat, separation of the seat from the base cannot occur since the stop 23 prevents such separation of seat and base, the latter stop causing turning of the nut 10. Thus, the seat 7 may swivel on the axis of the post 8 and the high and low positions of the seat maintained during swiveling movement.

It will be understood, that the nut 10 is preferably operatively connected to the post 8 before the seat 7 is placed in operative position of the base 5, since the pin 23 is more easily applied to the post before the seat is placed in operative position on the base.

While the foregoing has illustrated and described what is now contemplated to be the best mode of carrying out the invention, the construction is, of course, subject to modification without departing from the spirit and scope of the invention.

Having thus described the invention what is claimed and described to be secured by Letters Patent is:

l. A swivel chair having a base and a seat and comprising:

a pedestal column extending vertically from said base and provided at its upper end with a vertical cylindrical hole and top frictional bearing surface,

a freely rotational nut guided in said hole and provided with an upper flange in support engagement with said top surface and with an elongated cylindrical body with internal threads, and

a threaded post threadedly engaged with the threads of the nut and fixedly extending from the bottom of the seat, said post being longer than the nut body,

two spaced stops, one at the upper end of the post, facing downwardly, and adapted for stop engagement with the upper end of the nut when the seat is in its lowermost position, and the other at the lower end of the post and adapted for stop engagement with the lower end of the nut when the seat is in its fully raised position,

the nut, due to frictional engagement between the lower face of its flange with and the support face of the column, maintaining its nonrotational position during raising and lowering rotative movements of the post in the nut, said nut, when the same is engaged by one or the other of the stops, rotating in the cylindrical hole and, thereby, allowing the seat to swivel relative to the base.

2. A swivel chair according to claim 1 in which the bearing means comprises two longitudinally spaced plates having aligned holes in which the body is rotationally and slidingly plates is located adjacent the upper end of the pedestal column and constitutes the support with which the flange of the nut is frictionally engaged.

4. A swivel chair according to claim 1 in which the outer 3. A swivel chair according to claim 2 in which one of said 

1. A swivel chair having a base and a seat and comprising: a pedestal column extending vertically from said base and provided at its upper end with a vertical cylindrical hole and top frictional bearing surface, a freely rotational nut guided in said hole and provided with an upper flange in support engagement with said top surface and with an elongated cylindrical body with internal threads, and a threaded post threadedly engaged with the threads of the nut and fixedly extending from the bottom of the seat, said post being longer than the nut body, two spaced stops, one at the upper end of the post, facing downwardly, and adapted for stop engagement with the upper end of the nut when the seat is in its lowermost position, and the other at the lower end of the post and adapted for stop engagement with the lower end of the nut when the seat is in its fully raised position, the nut, due to frictional engagement between the lower face of its flange with and the support face of the column, maintaining its nonrotational position during raising and lowering rotative movements of the post in the nut, said nut, when the same is engaged by one or the other of the stops, rotating in the cylindrical hole and, thereby, allowing the seat to swivel relative to the base.
 2. A swivel chair according to claim 1 in which the bearing means comprises two longitudinally spaced plates having aligned holes in which the body is rotationally and slidingly fitted.
 3. A swivel chair according to claim 2 in which one of said plates is located adjacent the upper end of the pedestal column and constitutes the support with which the flange of the nut is frictionally engaged.
 4. A swivel chair according to claim 1 in which the outer face of the nut body is uniformly cylindrical, thereby adapting the nut to be slid from the bearing means, thereby to separate the seat and post from the pedestal column of the base. 